ARE you going to sing again?” the little boy asked the glamorous opera singer. She looked down at the top of his sandy head and recognised Brooklyn Beckham.

“Actually we weren’t,” Janet Shell admits later, still apparently sorry for disappointing England footballer David Beckham’s son even though three years have passed since the Spice Girl’s party they met at.

It was 2007, and the Port Sunlight-born mezzo-soprano was performing at the Christening of Geri Halliwell’s daughter, Bluebell Madonna, in the garden of their home.

“It was great. We were left to our own devices in the marquee in the garden and her little dog was coming round and barking at us and eventually she came and took it away,” recalls the former Wirral Girls Grammar School pupil.

“Posh was there with Brooklyn and Romeo and they were very cute and running around.”

Janet, who used to walk home from school pretending she was Julie Andrews, is used to performing for famous figures.

She has sung for John Major at 10 Downing Street, entertained guests at a party to mark Peter Sissons’ last day at the BBC with a rendition of The Leaving of Liverpool and coached Hot Chocolate’s Errol Brown, who rang her out of the blue one day.

“He told me his name but I thought ‘no, it can’t be’,” she recalls.

“He wanted some extra coaching before he went back out on tour so I worked with him for about six months.

“A lot of pop singers don’t realise the value of warming up their voice before they sing but actually the vocal chords are muscles so if you suddenly go in and sing a high note it’s a bit like running around the track without stretching first.

“He said he could sing for longer and feel happy about his singing because he had learned to do some warm up exercises.”

Last September, Janet appeared at the wedding of TV actress Sophie Winkleman to Lord Frederic Windsor in Hampton Court Palace.

“An email came in from the man who runs the Chapel Royal there saying ‘do you happen to be free in a couple of weeks’ time’,” she recalls. “You’re not going to turn that down!”

With two other singers, she performed a piece from Mozart’s romantic opera Cosi fan Tutte in front of a congregation that included Princess Eugenie, journalist Eve Pollard and Princess Michael of Kent.

“I was given the order of service the night before and I remember thinking, ‘gosh, I wonder what that’s worth’, but I thought ‘no, I’ll be a good girl’.

“It was wonderful and they all looked fantastic – everybody was in their best frocks. I had a bit of crisis over what I was going to wear and had to buy some new shoes for the event.

“We performed in the middle of the ceremony and it was a bit embarrassing because where we had to stand meant we turned our back completely on the rest of the Royal Family!”

If it wasn’t for her determination, Janet’s distinguished singing career would never have happened.

“I felt like I couldn’t possibly put myself in music college,” she says. “In hindsight, I probably could and they’d have liked to have had a voice they could put their mark on but I didn’t know that and the career advice I had at the time was ‘don’t do it, get a proper job’.”

So instead she became a music teacher, working at a school in Buckinghamshire, and commuting to London by train once a week for evening singing lessons at the Guildhall of Music and Drama.

Four years later she quit her job.

“I had to make a decision,” she says, “so in my mid-20s I suddenly thought ‘I don’t want to wake up and think I could have been a singer one day’ so I auditioned at the Guildhall and I got in.”

Despite her starstudded audiences, Janet says she is happiest when performing in front of a Merseyside audience.

“It’s when I’m able to come back to the Wirral and Liverpool after all this time away that is the most special moment for me.”